Splitting off cosmetics and unrelated test refactorings from a larger
CL reworking traced global handles.

Bug: v8:13141
Change-Id: I675cdbd4898346ab55b0db65d53e992f2eb95744
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3816671
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82295}